NEW YORK -- She was the first pure love of Eric Bana's life and the relationship lasted for 25 beautiful, exciting, temperamental years. Then came the accident.

"Mortally wounded," the star says with a sad shake of his head. "Leaking fluids. Needs an IV. May be time for the paddles."

And so his cherry-red'73 Ford Falcon XB -- Bana's first car and one he crashed in the 2007 Targa Tasmania road race -- currently sits in his Australian garage, near death.

But that doesn't mean she's finished with him yet.

Because this muscle-car still spurred Bana to make "Love the Beast," an idiosyncratic documentary about her (and the endless hours he and his mates spent under her hood).

And the time he spent filming that made him pass up some big-movie leads -- which took the actor straight into a juicy supporting role in outer space, as the villain in Friday's new "Star Trek."

In the hotly anticipated re-boot, Bana is Nero, a tattooed Romulan bent on revenge -- and with a particular grudge against young Spock. Yet while his character is fully in the series' tradition of brilliant bad guys, Bana says it's the story's optimism that appealed.

"There was a genuine, non-corny positivity that was real, and worth celebrating," he says, taking time out from screenings of his doc at the Tribeca Film Festival. "These kind of big summer movies have gotten so dark over the last five years; they're based on comic-book characters or whatever but you've got to tell your 10-year-old boy he can't see them. So it was nice being part of something that wasn't going to be one of those -- although I have to say I do enjoy the dark tales."

He must. In a very select film career, Bana, 40, has still racked up a list of pretty serious, and often somber, credits. "Black Hawk Down," "Hulk," "Troy," "The Other Boleyn Girl," "Munich" -- not a lot of laughs in those. Or in the first film that really grabbed people's attention, "Chopper," in which he played a vicious, real-life Australian criminal.

Which is all pretty funny, considering that the first half of Bana's performing career was spent -- well, being funny. Stand-up gigs. TV sketch comedy. Celebrity impressions (check out his painfully accurate jabs at Tom Cruise and Orlando Bloom on YouTube sometime). Not the usual training for a "serious" actor.

"I sort of came into this," he admits, "through a side door."

It didn't lead from a mansion, either. Bana was born in a slightly scruffy suburb of Melbourne, the youngest son of a German-emigre hairdresser and a Croatian-born manager at Caterpillar (the family name is actually Banadinovic). He was mad for sports and machines; school was another thing entirely.

"I didn't have any idea of becoming an actor," he says. "But I used to do a lot of stupid impressions of teachers and other students and it became a sort of currency to get me out of trouble. I began to realize, in my late teens, that there was something to it, and it was something I could do well. And that was very attractive."

Still, Bana didn't see it as a career. He liked cars and figured he'd end up being a mechanic; he flirted with dropping out of school and getting some job at a garage. But his father talked him out of it.

"Then one day a friend took me to a standup comedy venue," he says. "And the people onstage, except for maybe one guy, were hopeless. And they were all getting paid! So I thought, well, this is an outrage. This is a complete injustice. They're not funny and they're getting paid. And my mate said, 'Well then, why don't you do it?'"

A week later, Bana was climbing onstage.

"And it went pretty well and everything just started from there," he says. "Pretty soon I was working as a professional standup. Then I started doing sketch comedy on TV.. I had this career and I had no idea how it had happened."

It was a solid career too, branching out into comic films, live shows and his own TV special -- but none of it ever quite got outside Australia's borders. Which, Bana thinks now, was all to the good.

"The advantage I think (Australian actors) have is that, usually, no one in America sees us starting out," he says. "If you'd seen me in my first year of performing, I might never have gotten the opportunities I had here. We get to build up a body of work first. Also, since we are unfamiliar, there are no preconceived notions. None of my comedy had been seen here, so no one had formed any idea of what I could or couldn't do."

They had some ideas in Australia, or thought they had, which made Bana as crazed career criminal Mark "Chopper" Read seem like an odd choice at best in that 2000 movie.

"People thought it was going to be a farce, literally," he says. "So it was a huge leap of faith casting me in that. But it wasn't a leap for me because I knew I could do it. I was quite cocky about it, actually. But I don't put a lot of barriers in front of myself. If I think I can do something, I go for it, and I knew this was an opportunity lying in wait. The only scary thing was knowing it might never come round again."

The picture was a hit in Australia, and opened doors in America. But, Bana says, "that sort of thing is very short-lived -- it's got a shelf-life, that kind of success, and if you don't start doing more good work, it's all going to evaporate."

He looked hard to find it. He was Hoot in "Black Hawk Down" -- "an overwhelming, incredible shoot" -- then signed on to play Bruce Banner in Ang Lee's 2003 version of "Hulk." That was, apparently, an overwhelming shoot too -- but in a barely tolerable way.

"It wasn't a fun movie to make," he says. "Look, whether you have fun on a movie or not really stems from your director, and that was a difficult movie for Ang to make. It wasn't a lighthearted set or the most fun experience for the actors. But I have a lot of respect for him as a filmmaker. I thought it was extremely different from anything we'd seen in that genre -- in some ways I think it was one of the first of those films that had that darkness I was talking about. So it was exciting to be a part of, later. But it wasn't a fun shoot."

More enjoyable was "Troy," with its mammoth sets and all-star cast ("a genuine, epic experience -- I don't think I'll ever get the chance to work on a film of that size again"). And Bana had the best time ever on -- of all things -- "Munich," Steven Spielberg's despairing study of the massacre at the '72 Olympics, and the team the Israeli government dispatched to track down, and execute, the terrorists.

"I think that was our coping mechanism really, all of us," he says. "The subject matter was very heavy -- and we were committed to that -- but in between takes we kept things very light. I think we had to, really, or we would have gone insane. So it was a very fun set, very easy -- and also very collaborative, very meaningful, everything you'd want.. It was hard, really, when that one ended. That character stayed with me for awhile; it was like living with a ghost. But that happens sometimes, after a picture. It's like you're mourning something."

Not that Bana spends his months between pictures wandering his Melbourne house, talking to cinematic spirits. He's been happily married since 1997 to Rebecca Gleeson, a former publicist; they have a 10-year-old boy, Klaus, and an 8-year-old girl, Sophia. Bana still has the same friends he grew up with, and they still gather in the garage to work on cars.

"It's not a conscious thing," he says of the friendships he's held on to. "It's just, they're my mates, and they're my mates forever.. Of course, it takes more effort, once you get married, to stay in touch. It's definitely harder with this job, too, because there are large chunks of the year when I'm not home. But I feel that, and I put some effort into those relationships because I hold them very dear."

Although Bana's priorities have meant he doesn't work nearly as much as some other actors -- trying to stick to one film a year, and spend as much time home as possible -- this summer is practically a mini-festival for fans. First there's "Star Trek," opening Friday. Then, on July 31, he has a small part in Judd Apatow's "Funny People." Then the sci-fi romance, "The Time Traveler's Wife" -- with Bana starring as a temporally-unstuck librarian -- follows on August 14.

All very different projects. Yet they all started the same way -- with the blueprint of a script.

"The script is your starting point, and if the character's not there, you're really pushing it all uphill," Bana says. "But if it's there, then what comes next -- the prep time, the researching -- is something I really enjoy.. For example, in 'Star Trek,' right from the first draft, I could see that Nero was going to be interesting. You see him come on screen, and you say, 'OK, I can see why he's pissed off and wants to destroy the galaxy!' You're like, 'Well, Spock, you've got your work cut out for you here, mate!' And that really raises the stakes. That's what I look for. Not that you like the fellow. But that you understand him."